Knife blade or plug type electric switch



Nov. 22, 1949 c. A. ANDERSON KNIFE BLADE OR PLUG TYPE ELECTRIC SWITCH 2Sheets-Sheet 1 Filed July 18, 1946 jzzleizj arx Qarwza'e j /adm'saw c.A. ANDERSON 2,489,070

KNIFE BLADE OR PLUG TYPE ELECTRIC SWITCH 2 Sheets-Sheet 2 Nov; 22, 1949Filed July 18, 1946 ,Jiawezzfor: yam/ 7506 fzzakrsozz/ Patented Nov. 22,1949 UNITED STAT ES; PATENT OFFICE.

KNIFE BLADE OR. PLUG TYPE ELECTRIC SWITCH Clarence A. Anderson, SanDiego, Calif.

ApplicationJuly: 18;. 1945,, Serial No. 684,576

7 Claims.

My invention, relates toelectric switches of the knife type and asillustrated. and described: comprises a single throw double: pole knifeswitch although the: invention is. readily adapted to. a single: pole.-switch.

The primary object of my inventionis, the provision of a switch in whichthe'connectin elements are placed under tension when the circuit isclosed, thereby insuring a close and tight connection between all of theconducting parts of the switch with a minimum of resistance and lesslikelihood of arcing developing in the use of the switch.

Another and further object of my invention. is the provision ofduplicate. contact means at one end of the knife forming the. connectingelement between the. terminals of the. switch so that ifv for any reasonone set of parts does not. function properly to insure the flow ofelectric current therethrough, the other connection will operate toprovide this function.

Another and further object of my invention is the provision of a switchin which the various operating parts, being under tension in theirclosed position, as they are moved the surfaces are wiped clean and dirtcannot lodge between the contact points thereby causing an interrup--tion in the-circuit or interfere with the free flow of electricitytherethrough.

Another and further object of myinvention is the provision of a switchwhich in normal closed position is in dead center alignment; but uponthe initial and very slight movement of" the switch lever to openposition the switch lever is thrown off center, and due to the tensiontheswitch lever is automatically thrown clear of the connecting pointsthereby lessening the danger' of arcing which ofttimes results whenthese switches are opened and sometimes severely burns the operator ofthe switch.

These and other objects of my invention will be more fully and betterunderstood by reference to the accompanying drawings and in which:

Figure 1 is a top plan view of my improved switch;

Figure 2 is a sectional viewon linev 22' of Figure, 1 showing the switchin closed position;

Figure 3 is an end elevational View of the. switch;

Figure 4 is a sectional view on line 2-2 of Figure 1 showing the switchin open position; and

Figure 5 is a cross-sectionalview on lines. 5-51 of Figure 1.

Referring now specifically to the drawings and. in which like referencecharacters refer. to-

extending outwardly therethrough within which screws l6, iii are mountedby means of which the usual electrical conductors such as wires; cables.or the like can be. connected;

Screws ii, ll are provided which have. their heads mounted. on theunderside of the base In in a recess l8 and extend upward therethrough.

into the bases of each of the members. H and I2: andxprovidez means bywhichthe members II. and I2 are firmly fixed. tothe base member l0:

Extending upward from the bases of each of\ the members H and I2 are.side members t9 ami 2a, which; converge inwardly towards each other; attheir: outenor free ends and have knife members..2'.l,.2.l of a:connecting member pivotallymounted therein upon pins 22., 22 which haveenlarged. heads 23' and: 24'; on each endthereof,

both the side contacts of the side members 1 9 and 20- with the knife 2!of the pins 22, 22 through the knife 21"- and the connections beingfairly snug, although not sufiiciently tight to prevent the movement ofthe knife members 2|, 2-! upon the pins 22, 22 as a pivotal axis.

A nonconductor 25 is provided which connects the knife members 21, 2|and into which the ends of the knife blades 2!, 2i extend, each of theseknife members 2|, 2! having semicircular conductors 26;, 26 mounted.therein transversely thereof'with their ends projecting outward. fromthe knife members 2'1, 2!. with flat faces which contact against thenonconductor member 25,. with bolts 2T, 2'! extending through thenonconductor 25" and. through the semi-circu1ar conductors 26,16,thereby connecting the member 25 firmly to the, ends ofthe members 2|,21 whichextend into recesses 28, 28 formed in the. side of thenonconducting member 25. A handle 29 is secured by meansof a bolt as, tothe nonconductor 25. by. means of which the switch is opened. and;closed. by the operator as may be desired.

Mountedin:v recesses 3L3! by means of screws 32,, 3-2. the: heads. ofwhich are within the recess 65 I8 formedontheunderside. of the. basemember.

l, are elongated flat spring base portions 33, 33 of stirrup shapedconnecting members 34 and 35 in the opposite end of the base [B from theconnecting members I l and I2 heretofore described. Each of thesemembers 34 and 35 in addition to the base portions 33, 33 have inwardlyconverging side Walls with rollers 35, 36 mounted on the upper ends ofeach side wall of each member 34 and 35 by means of bolts 3'1, 37. thesebolts having enlarged heads 38, 38 spaced apart from each other aslightly lesser distance than the thickness of the knife members 2!, 25,so that as the switch is closed the knife members spread the arms ofeach of the members 3 5 and 35 thereby insuring close contact with thesides of the knife members 2 1, 2| as is usual with switches of thistype.

The base portions 33, 33 of the members 34 and 35 have flat springelongated portions extending therefrom through the ends of which thebolts 32, 32 extend the point of attachment of the base portions 33, 33to the member It) being offset with respect to the vertical planethrough the members 34 and 35 and the axis of the rollers 35, 33. Theouter periphery of the rollers 35, 33 extends into the path of travel ofthe outer periphery of the semicircular members 26, as the knife members2i, 2! are placed in closed position so that as the switch is placed tofinal closed position the rollers 33, 3t rotate pushing the members 34and slightly out of the vertical position (Figure 2) so that anelectrical connection is made between the rollers 35, 33 of the members26 secured in the ends of the blades 2|, thereby tending to push thearms 34 and 35 toward the arms II and I2 at the opposite end of themember, placing all of the connecting portions of the switch undertension.

Connecting ears 33, 39 having screws 43, 48 therein with the members 39,39 being connected to the bases 33, 33 provide terminal means to whichelectrical wires or the like may be secured for electrical conductingpurposes.

A stop block ii is mounted on the base member I3 against which thehandle 29 rests when in closed position, in which position the centersof the blade members 2!. 2i and the handle 29, the axes of the bolts 22and 37, 3'! together with the contact point of the members 25, 26 withthe rollers 36 are all in alignment, or in eifect a dead center positionin which position the switch will remain until force is exerted on thehandle towards opening the switch, and then due to the force exertedthrough the spring base members 33, 33 the knife portions will bequickly thrown clear of the heads of the bolts 38, 38 and the members 23thrown clear of the rollers 33, 36 thereby quickly and efiectivelybreaking the circuit and lessening the danger of arcin when theseswitches are used with high voltage circuits on switchboards and thelike.

From the foregoing description it is believed that the operation of theswitch will be readily and quickly understood in that the switch is putinto position on a switchboard terminal box or the like and connectedthrough the terminals with the proper wiring leading to the sections ofelectrical power on the one side and to the light circuit or the like onthe other.

Upon the handle being pushed into closed position the blades 2], 2ifrictionally engage between the heads 38, 38 on the bolts 31 normallysecuring contact. As the rollers 35, 36 engage the rounded surfaces ofthe members 26, 26 and the switch is closed members 34, 35 are cantedslightly out of vertical position producing a slightly wiping action onthe outer surfaces of the knives 2|, 2| and creating a lateral thrusttowards the handle 29 on the knives 2|, 2i thereby placing the wholestructure under tension and taking up any wear or looseness in any ofthe operating parts and insuring a tight connection for the operatingparts of the switch. As these switches are used, the constant bringingtogether of these parts keeps the surfaces clean and no carbonizing canresult and the operation of the switches is always certain.

When it is desired to open them, the handle is grasped by the operatorand pulled out in the usual manner and as explained above, when theblades are in dead center position the switch automatically kicks outbecause of the tension thereby lessening the danger of arcing or burningof the operatior and making the switch easy and quick to operate.

While I have described more or less precisely the details ofconstruction, I do not wish to be understood as limiting myself thereto,as I contemplate changes in form and the proportion of parts and thesubstitution of equivalents as circumstances may suggest or renderexpedient without departing from the spirit or scope of my invention.

What is claimed is:

1. An electric switch comprising in combination a non-electricalconductor base, a combined terminal and mounting for a movableconnector, a movable connecting member pivotally mounted on saidcombined terminal and mounting, a second mounting and connector having aspring base mounted on said base having spaced contact portions androllers movably mounted thereon, and a second connector mounted on thepivotally mounted connecting member adapted to engage the said rollersthereby placing the moving parts of the switch under tension.

2. An electric switch comprising in combination a non-electricalconducting base, a mounting for a connector mounted thereon, a connectormovably positioned on said mounting, a second mounting member havingspaced contact members thereon, rollers on said contact members, aspring member on which said second mounting member is positioned securedto said base and a contact member secured to said connector forengagement with the said rollers whereb a plurality of contacts isestablished with the connector and the mountings and connector areplaced under tension.

.3. An electric switch comprising in combination a non-conductor base, afixed terminal on said base, a connector pivotally mounted on said fixedterminal, a second terminal having a spring base portion, a stirrupshaped connecting link thereon having rollers at its free end, a memberon the free end of the pivotall mounted connector for engagement withthe periphery of the rollers on the stirrup shaped connector, and ahandle on the pivotally mounted connector, the rollers on the stirrupshaped connector extending into the path of the member on the free endof the pivotally mounted connector whereby when the switch is closed theconnecting members are placed under tension.

4. An electric switch comprising in combination a non-electrical basemember, a connector mounted thereon, a pivotally mounted switch memberon said connector, a second connector having spaced free ends mounted ona spring base on the said base member, rollers on the free ends of thesaid second connector, a handle secured to the free end of the switchmember and '5 a connector secured to the said handle and to the free endof the switch member having a rounded outer surface adapted to engagethe rollers on the second connector and place connecting parts undertension when the switch is closed.

5. An electric switch comprising in combination a non-electrical basemember, a connector mounted thereon, a pivotally mounted switch memberon said connector, a second connector having spaced free ends mounted ona spring base on the said base member, rollers on the free ends of thesaid second connector, a handle secured to the free end of the switchmember and a connector secured to the said handle and to the free end ofthe switch member having a rounded outer surface adapted to engage therollers on the second connector and place connecting parts under tensionwhen the switch is closed, the centers of the mounting for the switchmember, the rollers and the center of the rounded outer surface of theconnector on the handle being in alignment When the switch is closed.

6. An electric switch comprising in combination a non-electrical basemember, a connector mounted thereon, a pivotally mounted switch memberon said connector, a second connector having spaced free ends mounted ona spring base on the said base member, rollers on the free ends of thesaid second connector, a handle secured to the free end of the switchmember and a connector secured to the said handle and to the free end ofthe switch member having a rounded outer surface adapted to engage therollers on the second connector and place connecting parts under tensionwhen the switch is closed and a limit stop adapted to engage the handleportion of the switch member.

7. An electric switch comprising in combination a non-electrical basemember, a connector mounted thereon, a pivotally mounted switch memberon said connector, a second connector having spaced free ends mounted ona spring base on the said base member, rollers on the free ends of thesaid second connector, a handle secured to the free end of the switchmember and a connector secured to the said handle and to the free end ofthe switch member having a rounded outer surface adapted to engage therollers on the second connector and place connecting parts under tensionwhen the switch is closed, the centers of the mounting for the switchmember, the rollers and the center of the rounded outer surface of theconnector on the handle being in alignment when the switch is closed anda limit stop adapted to engage the handle portion of the switch member.

CLARENCE A. ANDERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 477,374 Klein June 21, 1892765,609 Badeau July 19, 1904 881,686 Hoadley Mar. 10, 1908 905,782Barnum Dec. 1, 1908

